Changes in biogeochemistry and carbon fluxes in a boreal forest after the clear-cutting and partial burning of slash

•A mature boreal spruce forest was clear-cut and treated with partial burning of logging residue.•The CO2 efflux decreased for two years after the burning treatment.•The net uptake of CH4 in soil decreased for one year after the clear-cut and burning.•The volatile organic compound (VOC) emissions were 100-fold for a short period after the clear-cut and burning.